[PATCH v12 5/7] arm64: pmu: Detect multiple generic PMUs and append counter
From: Jeremy Linton <hidden>
Date: 2017-01-10 17:17:50
Also in:
linux-acpi
Subsystem:
arm pmu profiling and debugging, arm64 port (aarch64 architecture), performance events subsystem, the rest · Maintainers:
Will Deacon, Mark Rutland, Catalin Marinas, Peter Zijlstra, Ingo Molnar, Arnaldo Carvalho de Melo, Namhyung Kim, Linus Torvalds
In heterogeneous CPU systems its likely that there are multiple PMU types. If a system is using the generic armv8_pmuv3 rather than a PMU with a hard-coded set of events then we want to uniquely identify each PMU in /sys. We do this by appending an "_x" to the pmu name. This then creates PMUs like, "armv8_pmuv3" and "armv8_pmuv3_1", "armv8_pmuv3_2" for a system with 3 PMU types. Signed-off-by: Jeremy Linton <redacted> --- arch/arm64/kernel/perf_event.c | 2 +- drivers/perf/arm_pmu.c | 20 ++++++++++++++++++++ include/linux/perf/arm_pmu.h | 1 + 3 files changed, 22 insertions(+), 1 deletion(-)
diff --git a/arch/arm64/kernel/perf_event.c b/arch/arm64/kernel/perf_event.c
index 57ae9d9..0fbd7ef 100644
--- a/arch/arm64/kernel/perf_event.c
+++ b/arch/arm64/kernel/perf_event.c@@ -1002,7 +1002,7 @@ static void armv8_pmu_init(struct arm_pmu *cpu_pmu) static int armv8_pmuv3_init(struct arm_pmu *cpu_pmu) { armv8_pmu_init(cpu_pmu); - cpu_pmu->name = "armv8_pmuv3"; + cpu_pmu->name = ARMV8_PMUV3_DESCRIPTION; cpu_pmu->map_event = armv8_pmuv3_map_event; cpu_pmu->attr_groups[ARMPMU_ATTR_GROUP_EVENTS] = &armv8_pmuv3_events_attr_group;
diff --git a/drivers/perf/arm_pmu.c b/drivers/perf/arm_pmu.c
index 37e241f..85566f6 100644
--- a/drivers/perf/arm_pmu.c
+++ b/drivers/perf/arm_pmu.c@@ -1035,6 +1035,7 @@ int arm_pmu_device_probe(struct platform_device *pdev, const struct of_device_id *of_table, const struct pmu_probe_info *probe_table) { + static int duplicate_pmus; const struct of_device_id *of_id; const int (*init_fn)(struct arm_pmu *); struct device_node *node = pdev->dev.of_node;
@@ -1075,6 +1076,25 @@ int arm_pmu_device_probe(struct platform_device *pdev, goto out_free; } + /* + * if this pmu declaration is a generic pmu and we have + * previously found a generic pmu on this platform + * then append a PMU number to the pmu name. This avoids + * changing the names of PMUs that are specific to a class + * of CPUs. The assumption is that if we match a specific PMU + * then it's unique, and another PMU in the system will match + * a different entry rather than needing the _number to + * assure its unique. + */ + if (!strcmp(pmu->name, ARMV8_PMUV3_DESCRIPTION)) { + if (duplicate_pmus) { + pmu->name = kasprintf(GFP_KERNEL, "%s_%d", + pmu->name, duplicate_pmus); + if (!pmu->name) + goto out_free; + } + duplicate_pmus++; + } ret = cpu_pmu_init(pmu); if (ret)
diff --git a/include/linux/perf/arm_pmu.h b/include/linux/perf/arm_pmu.h
index df1ba55..42b5edb 100644
--- a/include/linux/perf/arm_pmu.h
+++ b/include/linux/perf/arm_pmu.h@@ -161,6 +161,7 @@ int arm_pmu_device_probe(struct platform_device *pdev, const struct pmu_probe_info *probe_table); #define ARMV8_PMU_PDEV_NAME "armv8-pmu" +#define ARMV8_PMUV3_DESCRIPTION "armv8_pmuv3" #endif /* CONFIG_ARM_PMU */
--
2.5.5